Construction of Two-Dimensional Chiral Networks through Atomic Bromine on Surfaces.

Using atomic bromine and 2,6-diphenylanthracene (DPA), we successfully constructed and characterized the large-area 2D chiral networks on Ag(111) and Cu(111) surfaces by combining molecular beam epitaxy with scanning tunneling microscopy. The Br atoms distribute themselves periodically in the network with the maximum number of -C-H···Br hydrogen bonds. Density functional theory calculations demonstrate that the hydrogen bonds contribute to the stability of the Br-organic networks. In addition, by controlling the ratio of bromine atoms to DPA molecules, different patterns of Br-organic networks were obtained on Ag(111) surfaces. Further experiments with 2,6-di(4-cyclohexylphenyl)anthracene on Ag(111) produced analogous atomic bromine guided 2D chiral networks.